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Biomedical subjects

V Hruban

Publications and source records attributed to V Hruban.

At least 19 recordsLinked to original sources
PubMed1994

[Melanoblastoma in laboratory minipigs: a model for studying human malignant melanoma].

Human malignant melanoma is a progressively growing tumour mostly with a fatal prognosis during short time. Its frequency has doubled in some states of the USA during the last few years. Surgical treatment, which is still generally used, has very low efficiency due to the numerous metastases in different organs. An animal model is a necessary prerequisite to develop a new therapy methods. We have recorded primary cutaneous malignant melanomas as well as extensive metastases in the visceral organs in darkly pigmented laboratory minipigs. The primary skin tumours were mostly multiple and they showed a tuberous nodular form. The regular occurrence of tumours in a progeny of three specific mating types suggests the existence of genetic predisposition to malignant transformation. We discuss the use of this animal model for further studies and treatment of human malignant melanoma by our ischemization technique developed previously.

Animals↗
PubMed1991

Identification of medullary thymocytes by means of a monoclonal antibody.

A monoclonal antibody (IVA-1) reacting with bovine lymphoid cells differentiates the medullary and cortical zone of the thymus in cattle, pigs and sheep. The morphological picture indicates that the identified antigen most likely points out the route of maturation of the thymocytes. The antibody could be of use in studies of the development of thymocytes.

Animals↗
PubMed1989

The tissue distribution of Ia- and IgM-positive cells in adult and newborn miniature pigs.

Distribution of Ia- and IgM-positive cells was compared in tissues of adult and newborn miniature pigs, using indirect immunoperoxidase and immunofluorescent techniques with monoclonal antibodies. The different distribution patterns were found mainly in adult jejunum and kidney. Both IgM- and Ia-staining were ascertained in the lamina propria between the Lieberkühn crypts and in the lymphoid follicles of the jejunum. Moreover, IgM-positive cells were demonstrated in the crypts while Ia-reaction was seen in the lamina propria of the villi. In the kidney, IgM-staining was limited to the glomeruli. On the contrary, a distinct Ia-reaction was found mainly in intertubular structures. Small differences in IgM- and Ia-positive cell distribution were also noted in the mesenteric lymph nodes and in the spleen. Developmental changes of the adult distribution patterns (chiefly that of IgM-positive cells) were found in all tissues studied at 2 days of age.

Aging↗
PubMed1989

Experimental devascularization (devitalization) of the rectum and sigmoideum.

In 6 laboratory pigs, devascularization (devitalization) of the rectum and the adjacent part of the sigmoideum was carried out by the vasa rectalia cranialia et media ligatures with simultaneous aboral closure of the rectum at the base of the lesser pelvis and oral closure at the borderline between the rectum and the sigmoideum. The devascularized rectum was not removed but left in situ. Terminal colostomy was established. Laparotomic revision was carried out after 12 weeks, colostomy was removed and continuity of the intestine was reestablished by insertion anastomosis, by suture of the end of the colon to the anal mucosa and skin. In further two pigs, devascularization of the rectosigmoideum was carried out with colostomy and reconstruction was carried out after 12 weeks by procto-sigmoideo-anastomosis. In another 2 animals, devascularization was carried out on the lower part of the sigmoideum and continuity was immediately renewed by end-to-side sigmoideo-sigmo-ideoanastomosis. All revisions indicated that the devascularized necrotic segment shrank to form a minute fibrous tissue residue, anastomosis was patent and continence was retained for colo-proctoanastomosis. The described techniques are technically simple and could be employed as palliative surgical methods for inoperable tumours in the region of the rectum and lower part of the sigmoideum.

Anal Canal↗
PubMed1989

[Use of the tourniquet in gastrointestinal surgery].

Experimentally induced total or partial intestinal obstructions (ileus) in pigs were surgically treated by means of a tourniquet technique. A lace used in obstetrics for ligation of umbilicus served as the tourniquet. The lace was protracted around an intestine, both ends were threaded through 7-10 cm long rubber tube and fixed by Pean's forceps. During application of the tourniquet we performed suction of the ileus content, devitalization or resection of the affected intestinal segments and intestinal anastomoses. Since the tourniquet provides a flexible compression of intestine with minimum mechanical damage, manipulation without danger of instrument release, and it has negligible cost, this tool gives supposition for the possible use in human surgical praxis.

Animals↗
PubMed1988

Changes of clinical biochemical values after bilateral nephrectomy and allotransplantation of the kidney in pigs.

In a series of 10 healthy pigs, the normal ranges of the following biochemical parameters in blood serum were assessed: creatinine, urea, mineralogram (Na, K, Cl), uric acid, bilirubin, total protein, cholesterol, blood lipid level, thymol turbidity reaction and activities of alkaline phosphatase, alpha-amylase and transaminases. The changes of these values were followed up in two pigs after bilateral nephrectomy and in 18 pigs subjected to orthotopic allotransplantation of the kidneys. The examination confirmed that creatinine and urea are the most important values with a prognostic impact. However, other biochemical values signalize also renal dysfunction. In the mineralogram, values of Na and K ions are important indicators. Deterioration of renal functions was associated as a rule with a decline of alpha-amylase and alkaline phosphatase. The other examinations did not display any marked changes during renal damage.

Alkaline Phosphatase↗
PubMed1988

Joint report of the first international comparison test on swine lymphocyte alloantigens (SLA).

The first international comparison test on swine lymphocyte alloantigens (SLA) was held in Helsinki, Finland in July 1986. The results reported were based on a comparison of 157 alloantisera originating from six laboratories. The antisera were tested against a selected panel of 264 lymphocyte samples belonging to four laboratories. The most common breeds in Europe were chosen for this first comparison test (Landrace and Large White). Eighteen of the 31 previously known specificities were confirmed and a new nomenclature was established.

Animals↗
PubMed1988

Interspecies cross-reactivity of bovine lymphocytotoxic sera with pig lymphocytes.

Forty-three bovine BoLA antisera were tested on pig lymphocytes by a microlymphocytotoxicity test. Twenty-five were found to be cytolytic. Fifteen sera detected the A blood group antigen on porcine lymphocytes but showed no reaction with the J antigen on bovine lymphocytes. Six BoLA reagents reacted with all pig cells tested. Cross-reactions with SLA antigens were observed in only four sera, the highest correlation being recorded with SLA-W7 (r = 0.87). Bovine alloantisera are not of value for SLA typing.

Animals↗
PubMed1988

Polymorphism of the SLB serologically defined (non-MHC) alloantigenic system in pigs.

Six new antigenic specificities (designated SLB-2 to SLB-7) detectable with polyclonal reagents in the complement-dependent lymphocytotoxic test were determined in the SLB alloantigenic system of pigs. The SLB specificities (including the previously described SLB-1) are controlled by 13 alleles. An analysis of a further 121 double backcross matings (with 817 offspring) confirmed that the products of SLB alleles segregated independently of the SLA haplotypes (swine MHC). In addition, in 112 families of the same mating type (with 746 progeny) the map distance of the SLB locus and the highly polymorphic L blood group locus was found to be 7.82 centimorgans in the heterogametic sex and 12.57 centimorgans in the homogametic sex.

Alleles↗
PubMed1988

The devitalization of the stomach by a devascularization technique.

Different parts of the stomach in healthy animals (pigs) were devitalized (devascularized) by eliminating the blood supply and left in situ. In model experiments, parts of the stomach were chosen for the devitalization with respect to most frequent location of carcinomas. The operation technique consisted of a complete ligature of perigastric vessels, bling enclosure of the cranial part of the duodenum with two ligatures with a possible application of a seromuscular suture and transverse cutting of the oral part of the stomach and its enclosing by a suture with a partial invagination of the wall. The passage was renewed by a gastroenteroanastomosis, some of the used modifications of the operation technique according to Billroth II (Schlater-Pólya). A method was mostly proposed with an interposition of the jejunal loop, which bridged the site of the devitalized part of the stomach. In 10 to 20 weeks the stomach tissue was stepwise degraded and it was replaced by fibrous tissue. The operation technique is simple; it could be applicable as a palliative or possibly therapeutic intervention in the case of inoperable tumours in human practice.

Animals↗
PubMed1988

A technique of the segmental devitalization of kidneys in experiment.

With the help of partially overlapping parenchymatous sutures, different renal segments were devitalized. After 8 weeks, a fibrous conversion occurred in devitalized part of the kidney. For the orientation during establishing the sutures, a topographic schematic diagram was used, which is simple and quite satisfactory for the use in practice. The study was performed on minipigs (21 x unilaterally, 3 x bilaterally) without any exitus of the experimental animals. A long series of experiments was performed in 37 rats on one kidney and in 40 rats bilaterally. Only in 3 rats the cause of the exitus was obviously in a connection with eliminating more than 70 to 75% of the renal parenchyma from the function. The devitalization technique presents good results in both series of the experiments. Possibilities of its use in the clinical practice in cases, where the resection therapy is being used currently, are discussed.

Animals↗
PubMed1987

Morphology of regressive changes in the kidney following experimental ischaemia.

Total or partial renal ischaemia was studied in rats and pigs in a series of experiments, after total devascularization (ligature of renal vessels and ureter); ligature of isolated renal artery; experimental embolization of renal artery by non-resorbable material; devascularization of a specific renal segment by deep, strangulating sutures. Morphological studies showed that the resulting necrotization is represented most frequently by coagulation necrosis, less frequently by colliquating necrosis. Occlusion of the renal artery by embolization or ligature leads only to partial necrotization or atrophy. Total devascularization of the renal hilus or total devascularization of a specific renal segment by strangulating sutures leads to total destruction of the devascularized (devitalized) tissues. Within 8-12 weeks, the whole organ changes into a small residue of connective tissue. The possibility of the use of the devascularization technique in the treatment of tumours is discussed.

Animals↗